Paint rollers have been used since the late 1940's for applying paint to a relatively large area. The conventional paint roller is not used in tight areas, nor close to edges and inner corners, as it cannot apply paint in a good straight line, and the structure of the rollers prevent them from being used close to tight areas. Often the end of the known cylindrical paint roller becomes covered with wet paint, so that when the roller is used close to an inner corner with an adjacent surface, such as a ceiling or floor, paint from the end of the roller is transferred to the adjacent surface. Additionally, devices used to retain the roller on its shaft often mar the adjacent surface. Various shields and guides have been proposed to keep the end of the roller both clean and spaced from the adjacent surface. Spacers, however, prevent the roller from applying paint up to an edge, or into a corner.
A brush or other small tool is necessary to cover such areas in order to finish a painting job. This system has several disadvantages. The painted surface often shows a different texture where different implements have been used; multiple painting tools must be cleaned; and covering these small areas can be extremely time consuming.
A number of painting tools have been proposed for applying paint into corners, up to edges, and in other tight areas. U.S. Pat. No. 2,765,486 describes a conical shaped paint roller having an angled end, so that only the contact portion of the roller reaches to the edge. Unfortunately a conic shape does not easily roll along a straight line, thus making both loading the roller, and applying paint with it, quite difficult. A loose bearing and an internal roller are provided to attempt to compensate. However, the result is an unwieldy loose roller, which still does not easily roll in a straight line.
U.S. Pat. No. 3,023,443 also describes a cone shaped roller for painting edges. The angle of the cone does serve to space the end of the roller from the adjacent surface in a corner, however in order to roll straight, the roller is mounted on a series of wheels which actually prevent the contact edge from applying paint right into a corner angle. Multiple tools are still required to complete a painting job.
Both of these patents incorporate an extreme conical shape which would likely result in an inconsistent amount of paint being available for distribution due to the extreme diameter change.
Bevelled rollers are proposed in U.S. Pat. No. 3,205,526 and in U.S. Pat. No. 2,936,474 for applying a small amount of paint up to the edges or into corners. These are similar to the conical rollers, and only the contact surface reaches to the edge. However, these devices seem only suitable for painting a very small area. Indeed these devices seem to be used to fill in the areas the conventional roller cannot reach.